Comparing the SEED Semi-Solid Process to Low Pressure Permanent Mould in the Production of 4mm Thick Aluminum A356 Covers

摘要

In order to compare the semi-solid SEED casting process to the Low Pressure Permanent Mould process (LPPM), the same part has been produced in aluminium A356 (AlSi7Mg04) using the two methods. The processes were first compared from an operational standpoint: pouring temperature, filling sequence, production rate and mould maintenance. In addition, the metallurgical quality of the castings was evaluated by measuring the tensile properties at 6 locations in the part; the metallographic structures were also compared. Filling and solidification modeling allowed the prediction of the filling sequence and local solidification times everywhere in the casting. The SEED process was generally found to deliver a finer structure, a near net shape casting and a much higher productivity. LPPM parts were more uniform in structural and mechanical properties as verified at 6 locations in the castings.